{"title":"Investigating Acceptable Level of Travel Demand before Capacity Enhancement for Signalized Urban Road Networks","authors":"Ö. Baskan, Huseyin Ceylan, Cenk Ozan","doi":"10.18400/tekderg.464260","DOIUrl":null,"url":null,"abstract":"Increasing travel demand in urban areas triggers traffic congestion and increases delay in road networks. In this context, local authorities that are responsible for traffic operations seek to strike a balance between traffic volume and capacity to reduce total travel time on road networks. Since intersections are the most critical components of road networks in terms of safety and operational issues, adjusting intersection signal timings becomes an effective method for authorities. When this tool remains incapable of overcoming traffic congestions, authorities take expensive measures such as increasing link capacities, lane additions or applying grade-separated junctions. However, it may be more useful to handle road networks as a whole by investigating the effects of optimizing signal timings of all intersections in the network. Therefore, it would be useful to investigate the right time for physical improvements on the road network to avoid premature investments considering limited resources of local authorities. In this study, effects of increasing travel demand on Total Travel Cost (TTC) is investigated by developing a bi-level programming model, called TRAvel COst Minimizer (TRACOM), in which the upper level minimizes the TTC subject to the stochastic user equilibrium link flows determined at the lower level. The TRACOM is applied to Allsop and Charlesworths’ network for different origin-destination demand matrix multipliers. Results revealed that TTC values showed an approximate linear increase while the travel demand is increased up to 16%. After this value, TTC showed a sudden spike although the travel demand was linearly increased that means optimizing signal timings must be supported by applying psychical improvements.","PeriodicalId":49442,"journal":{"name":"Teknik Dergi","volume":null,"pages":null},"PeriodicalIF":0.8000,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"2","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Teknik Dergi","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.18400/tekderg.464260","RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"ENGINEERING, CIVIL","Score":null,"Total":0}
引用次数: 2
Abstract
Increasing travel demand in urban areas triggers traffic congestion and increases delay in road networks. In this context, local authorities that are responsible for traffic operations seek to strike a balance between traffic volume and capacity to reduce total travel time on road networks. Since intersections are the most critical components of road networks in terms of safety and operational issues, adjusting intersection signal timings becomes an effective method for authorities. When this tool remains incapable of overcoming traffic congestions, authorities take expensive measures such as increasing link capacities, lane additions or applying grade-separated junctions. However, it may be more useful to handle road networks as a whole by investigating the effects of optimizing signal timings of all intersections in the network. Therefore, it would be useful to investigate the right time for physical improvements on the road network to avoid premature investments considering limited resources of local authorities. In this study, effects of increasing travel demand on Total Travel Cost (TTC) is investigated by developing a bi-level programming model, called TRAvel COst Minimizer (TRACOM), in which the upper level minimizes the TTC subject to the stochastic user equilibrium link flows determined at the lower level. The TRACOM is applied to Allsop and Charlesworths’ network for different origin-destination demand matrix multipliers. Results revealed that TTC values showed an approximate linear increase while the travel demand is increased up to 16%. After this value, TTC showed a sudden spike although the travel demand was linearly increased that means optimizing signal timings must be supported by applying psychical improvements.
期刊介绍:
The scope of Teknik Dergi is naturally confined with the subjects falling in the area of civil engineering. However, the area of civil engineering has recently been significantly enlarged, even the definition of civil engineering has somewhat changed.
Half a century ago, engineering was simply defined as “the art of using and converting the natural resources for the benefit of the mankind”. Today, the same objective is expected to be realised (i) by complying with the desire and expectations of the people concerned and (ii) without wasting the resources and within the sustainability principles. This change has required an interaction between engineering and social and administrative sciences. Some subjects at the borderline between civil engineering and social and administrative sciences have consequently been included in the area of civil engineering.
Teknik Dergi defines its scope in line with this understanding. However, it requires the papers falling in the borderline to have a significant component of civil engineering.